Each hole shows two lists. Write one regular expression that matches every string in the match column and none in the reject column. Strings light up green or red as you type, so you can see where you stand.
Your score is the number of characters in your pattern, so shorter is better — this is golf. Par is the length of
a known solution. Beating par is possible on most holes. Write the pattern only: ing$, not
/ing$/. It runs as a JavaScript regex in your own browser, unanchored, case-sensitive, no flags.
A new five-hole puzzle appears at 00:00 UTC. Progress and streaks are kept in your browser's local storage and are never sent anywhere. There is no account, nothing to buy, and no ads.